The background description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.
Internal combustions engines combust an air and fuel mixture within cylinders to produce drive torque. More specifically, the combustion events reciprocally drive pistons that drive a crankshaft to provide torque output from the engine. The fuel is delivered to the engine by a fuel system. The fuel systems of some vehicles include a plurality of fuel tanks. For example, some fuel systems include a primary fuel tank and a secondary fuel tank that share a common filling neck.
Fuel levels within the fuel tanks are monitored, and the vehicle operator is informed of the amount of fuel remaining in each tank. More specifically, a fuel level sensor is provided in each tank. Each fuel level sensor is responsive to the fuel level in a respective tank and generates a signal based on the fuel level. The amount of fuel remaining is determined based on the signal.
Some fuel systems further include a transfer pump (TP) that supplies fuel drawn from the primary fuel tank to the secondary fuel tank. Conventional TP diagnostic systems do not diagnose the TP when the secondary fuel tank is full. Further, vehicle operators may regularly fill the secondary fuel tank to full, and thus, the diagnostic systems may never detect a failed TP.